Watch-crystal



(No Model.)

0. F. ALLEN. Watch Crystal.

No.. 230,214. Patented July 20,1880.

"- TERS. FHOTO-LITHOGRAPMER, WASHINGTON D C.

UNITED .STATES PATENT OFFICE.

CHARLES F. ALLEN, OF SOUTH ABINGTON, MASSACHUSETTS.

WATC H -C RYSTAL.

SPECIFICATION forming art of Letters Patent No. 230,214, dated July 20, 1880. Application filed May 15, 1880. (No model.)

To all whom it may concern:

Be it known that I, CHARLES F. ALLEN, of South Abington, in the county of Plymouth and State of Massachusetts, have invented certain new and useful Improvements in WVatch- Crystals, of which the following is a full, clear, and exact description.

This invention relates to the preparation of the upper or outer surface of a crystal or dial of a watch in such manner that times of appointments or meetings, 850., may be indicatcd thereon in a simple manner, and thus by such indication the person carrying the watch will be reminded of such appointment and be able to keep the same; and the invention consists in grinding or otherwise preparing the upper or outer surface of the crystal or dial ot' the watch at or over the circle of figures indicating the hours and minutes, as well as the circle indicating the seconds, so that a mark can be made on such prepared portion of the surface by a lead-pencil or other marking device, all substantially as hereinafter full y described, for the purpose specified.

In the drawings my invention is illustrated, Figure 1 being a front view of a watch having a portion of the outer or upper surface of its crystal prepared as hereinafter described Figs. 2, 3, and 4, cross-sections of different forms of such prepared watclrcrystals.

In the drawings, A represents a watch, in which a is the crystal, 0 and d the minute and hour hands,fthe circle indicating hours, 9 the circle indicating seconds, and h the second-hand, all as ordinarily in watches, and needing no particular description herein; 1, the prepared portion of the surface of the watch-crystal at the hour and minute circle f, and m the prepared portion at the circle h of seconds. These portions l and m of the surface of the crystal, in the present instances, are made by grinding the upper or outer surface of the watch-crystal at that part of it at or over the circle of hours and minutes and circle of seconds and coincident with said circles, and which grinding roughens or prepares the surface of the watch-crystal at these portions, so that a mark can be made on such prepared surface by a lead-pencil or other marking device.

In the use of this invention, supposing a person having his watch-crystal prepared as above described makes an appointment to meet another party-say at four oclock p. 111.; then with his lead-pencil he makes a mark on the prepared portion 1 of the surface over or at the figure 4, as shown at n, Fig. 1, thus indicating the hour of appointment, which mark a will then be a constant reminder to him of the engagement every time he looks at his watch to note the time of day, and obviously by such reminder he will not forget the appointment, but will thereby be sure of keeping it. \Vith the prepared surface at over or at the circle of seconds, if a person desires to note the sec onds of any passing circumstance, such as a horse racing, he can mark on the prepared portion at in a similar manner. and thus tune in seconds the movements of the horse in running of the race, as is obvious.

This invention is particularly described as being applied to the crystal of a watch. It is obvious, however, that the dial-plate itself can be prepared in asimilar manner.

Although the watch-crystal is herein described as being prepared by grinding, obviously it can be prepared or roughened in any other nmnner-such as, for instance, by the well-known process called the sand-blast, and it is not intended tolimit the invention to any particular manner of preparing the sur face of the crystal for the purposes intended, but grinding or the sand-blast are the best and most practical ways.

In some forms of watch-crystals, in lieu of its upper surface, its ed ge can be prepared as shown at l, more particularly in Fig. l.

The preparation of the surface ii the crystal over the circle of seconds can be dispensed with, if desired.

Having thus described my invention, what I claim, and desire to secure by Letters Pat.- ent, is-

A watch-crystal having a portion of its surface prepared to constitute a tablet for receiv ing marks, substantially as and for the purposes hcrein specified.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHAS. F. ALLEN.

YVitnesscs:

EDWIN W. BROWN, W. S. BELLows. 

